Steam Trap Condensate Load and Required Capacity

The running condensate load (heat duty / latent heat) and the required trap capacity (load x a 2x-3x safety factor) at the operating differential - undersize it and the equipment floods on warm-up. The trap is selected from the manufacturer's capacity chart at the actual differential; warm-up, modulating, and stall conditions can demand a larger factor or a different trap type. Not the IMC 307 cooling-coil condensate drain.

condensate_lbhr = heat_duty_btuhr / hfg_btulb; req_capacity_lbhr = condensate_lbhr x safety_factor (2x typical, 3x warm-up / modulating).

First-principles condensate-load relation and the safety-factor practice, by name; the latent heat is from the ASME steam tables. Not edition-bound.

The condensate load is the heat duty divided by the published latent heat at the operating pressure; the safety factor is standard practice.

Estimate. AHJ and licensed professional govern.

Field names used by the API: heat_duty_btuhr, hfg_btulb, safety_factor, condensate_lbhr, req_capacity_lbhr

• Latent heat hfg from the saturated-steam table at the operating pressure (user-supplied for an off-table pressure)ASME steam tables
• Safety factor 2x typical, 3x on warm-up / modulating service; higher factors for stall conditionssteam-trap selection practice
• Selection the trap is sized from the manufacturer's capacity chart at the actual differential pressuremanufacturer capacity chart